Farmers' local knowledge is comprised of structured systems of classification and self management governing resource use. These knowledge systems are dynamic, responding to, and developing from location-specific agro-ecological changes. They contain sets of empirical observations about local environments and are often expressed using farmers' own terminologies. They are accessible to, and developed by, those members of a social group charged with specific resource management and production responsibilities (Fernandez, 1994).

Because a basic social differentiation6 among adult, economically active members of a society is "gender"7, responsibility for different activities is distributed along gender lines; in other words, men and women. "Gender" refers not to women alone, but to the socially constructed roles of, and relationships between, men and women in a society. This necessarily implies addressing the different roles and relationships of women and men along other lines such as age, class, ethnicity, etc. In other words, poor women may have quite different responsibilities and roles (and therefore needs and priorities) in a society than better-off women, as may resource-poor women and better-off men.

6 There are other socio-economic differentiations such as class, ethnicity, age etc. For example, a male farmer working on a large estate producing cash crops may hold different knowledge from resource-poor small-scale male farmers and/or female farmers producing primarily food or subsistence crops.

Through the resulting division of labour, which is often very clear cut, men and women develop and generate specialized knowledge, even though they may retain a general knowledge of various activity areas. The knowledge and experience gained is, in turn, transmitted to group members responsible for similar activities in the future (Fernandez, 1994). This includes specialized knowledge of the diverse species, varieties, and agro-ecological systems with which they work.

I. Men's and women's different knowledge, priorities, and needs in PGR conservation and utilization

In much of the developing world, the on-farm and in-situ conservation and use of plant genetic resources begins with women. As farmers, they are responsible for growing and collecting food. Rural women are also largely responsible for the use and management of natural resources to provide daily domestic household needs including water, fuel, fodder, food, medicinal products and fibre. The processing and storage of food crops is also mainly their responsibility. With the increased monetization of the economy, men often specialize in producing cash crops for the external market. In this way, specific spheres of activity become the specialized domains of either men or women as they develop their expertise over time, and indeed, generations.

Perhaps the most well-known case is from South America which illustrates the extent of the knowledge that women have of seed diversity in their area. A few of the older women farmers in the Quechua communities of the Andes have been found to hold specialized knowledge of plant breeding, which has been handed down and improved over generations.

Potatoes are normally, propagated via asexual reproduction, by planting whole tubers or sections; the resulting plants are 'clones' whose characteristics are identical to those of the Parent' potato. However, a few of the old women farmers in the province of Cuzco, use true potato seed, a practice which has been all but abandoned. Older people who came to their community from the highlands to help with the harvest taught the Quechua women about the fruit of the potato plant, which contains the seed and this traditional method of propagation.

Since the potato's centre of origin is in the Andes, there are countless varieties in the region. People have different uses for each type. Using seed for propagation enables the women to breed new varieties with characteristics which they themselves choose. Before harvesting the potato crop, the women collect the fruits and store them in a large ceramic bowl outside the house where they remain until the following October. By then they have become black and rotten. Allowing the fruits to rot before planting the seeds is an essential part of the process, since it produces chemicals which activate the dormant seeds prior to germination.

The seeds are planted just before the rains, and the plants are allowed to grow until they produce tiny tubers. These foundation seed potatoes are then harvested and put away until the following year, when they are planted out and produce first-generation tubers. The products of this harvest, 'grandchildren' of the original seeds, are used for 'tuber seeds'. Women sort the 'tuber seeds' by shape and colour and other desired characteristics, often dividing them into as many as 12 types. These are usually distributed among their children, who plant them as food crops; some are also given away in sets as wedding presents to help young couples get a start.

II. Women conserving, developing, and utilizing less common PGR

The fundamental need for the conservation of PGR is their conservation in situ in their natural ecosystems and habitats and the maintenance and recovery of those resources in danger of extinction in their natural environments. Women's special knowledge of the value and diverse uses of plants for nutrition, health and income has important implications for the conservation of plant genetic resources. The decision to conserve less common plant species and varieties and to select which crop varieties to grow and how depends, to a large extent, on their usefulness to the farmer and the community. Women are also key decision makers in determining which food and other products to keep for home consumption, and which to sell at the local market.

Case Study ii: Landraces and Food Security in the Andes (Rea, 1995)

An example from the Andes shows that sometimes decisions taken by men to grow crops do not meet women s needs. At the "Gene Traders' conference in London in 1992, Miguel Altieri showed a slide of a woman farmer planting her own potatoes, hidden in her skirt, while her husband was looking the other way. Agricultural advisors had convinced her husband that planting one crop, Desiree, would increase his yield and income, and confirm his identity as a modern farmer. His wife, instead, valued the variety of landraces grown traditionally by the family for specific properties, including: early maturation, frost resistance, nutritious value, unusual taste, quick cooking time, and resistance to blight. Her family's food security depended on this diversity and the aversion of risk, and she is bound, by custom, to pass on tubers of each variety to her daughter on marriage, for the next generation (Rea, 1995).

III. Seed selection

It is estimated that ninety per cent of the planting materials used in developing countries is produced by the farmers themselves, ie. from saved seed (Spillane, 1996). The selection of wild genetic resources for home planting, of seeds for conserving for next year's planting and of vegetative propagatory material, and of the mixture of plant species to intercrop in gardens and fields is usually carried out by women. This selection is a sophisticated process that takes into account many different genetic characteristics and traits: organoleptic properties that confer taste, color, palatability and texture; resistance to pests and diseases; adaptation to soil and agro-climatic conditions and so on. The selection criteria are built up and developed over years of experience with a view to minimizing risk (i.e. reducing the losses from climatic vagaries and pest and disease attacks and optimizing production on different sites) and ensuring food security and secure livelihoods.

Case Study iii: Seed and Plant Selection and Use in Zimbabwe (Chimedze and Muntemba, 1995)

A study from Zimbabwe showed that through their daily work, managing soils and other land-based resources, women have accumulated intimate knowledge of their ecosystems, including the management of pests, the conservation of soils, and the development and use of plant genetic resources. Over years of work in the field, one researcher found women selecting specific seed to respond better to the various soil types and growing conditions. In fact, women in Zimbabwe do not, in general, buy seed for the basic food under their control, i.e. various millets, sorghum, groundnuts, and sweet potatoes; rather they select seed, looking for particular traits such as stability, disease resistance, drought tolerance, palatability, and storage quality.

Women have identified which plants to grow where in order to control pests and diseases. They intercrop, mingling plants that complement each other. They continually research and develop improved ways of storing produce from one agricultural season to the next. Their role in in-situ plant genetic resource conservation and use is invaluable, as they continue to develop genetic diversity, preserving cultivars which are environmentally sustainable and socially acceptable.

IV. Home gardens as "experimental stations"

In many households, women manage those components of the farming system that contain high levels of biodiversity such as home gardens - and make extensive use of gathered species and tree products. Women also make extensive use of wild patches and marginal areas within community lands where they gather traditional vegetables, condiments, and other (medicinal) plants that are crucial for the nutritional well-being and health of rural families throughout the world. In this way, rural women practice "in-situ conservation" in their home gardens and fields as well as in the common property resources (woodland, wetlands, etc.) that they utilise for wild plants and other products.

In Northeastern Thailand, the home garden is important as an informal 'experimental station' in which women transfer, encourage and tend indigenous species, trying them out and adapting them for use. As a result, these gardens often represent a refuge where less common species and varieties are preserved.

One study, malting use of interviews, focus groups and household surveys, collected information from 60 of 110 households in a village about their different home gardens. These home gardens contained 230 different plant species; individual garden diversity ranged from 15 to 60 different species. Non-domesticated plants were found in 44 (88%) of the gardens. Of all of the plants recorded during the surveys, 29% were classifiable as non-domesticated species. However, there existed considerable variation between the individual gardens. While some contained no non-domesticated plants at all, the garden which was most diverse contained 10 different non-domesticated plant species.

The researchers concluded that the considerable variation among the gardens was probably related to the high degree of control exercised by individual women with respect to plant choice and management. Home gardens are tailored to each woman's own practices, although personal constraints such as off-farm employment, family size, household composition and local traditions are of influence on the number and variety of non-domesticated species. Most plants are used for food, although a number of women grow plants also for their medicinal, religious or decorative value. While some of the non-domesticated species appeared spontaneously, a sizable number of plants were taken from the wild or obtained from friends, neighbours, other villages, and even government agencies. A few of the plants had been deliberately spared when the forest was cleared for further house-building.

Through their experimentation, practices and preferences, and their control over the gardens, women have increased the probability that these wild plants and less common species and varieties will be maintained over time. This is increasingly important as rapid economic and population growth in the region drastically affect the forest areas and threaten potentially useful plant genetic resources. Women's house gardens, a form of traditional agriculture, can provide not only a source of stability in the face of these changes, but also conserve a multitude of plant genetic resources to feed their families and communities, among other uses.